|Shields Jr, Fletcher|
Submitted to: Proceedings of the World Environmental and Water Resources Congress Conference
Publication Type: Proceedings
Publication Acceptance Date: 1/10/2008
Publication Date: 5/12/2008
Citation: Shields Jr, F.D., Knight, S.S., Lizotte Jr, R.E. 2008. Kondolf Diagram for River Restoration. In Babcock, R.W. and Walter R. (eds.) Proceedings of the World Environmental and Water Resources Congress Conference. American Society of Civil Engineers, Reston, VA. CD-ROM.
Interpretive Summary: River ecologists have found that floodplain lakes and sloughs that are attached to the river during higher flows (backwaters) are extremely valuable habitats, but these areas are undergoing rapid degradation due to sedimentation and pollution. Several techniques have been proposed and demonstrated for restoring the ecological quality of these areas, but methods for evaluating the effectiveness of the techniques are lacking. An approach for evaluation suggested by another scientist was applied to a backwater restoration project using a computer model that simulated backwater levels for a given set of river conditions. This method will assist others in planning, design and evaluation of river backwater restoration projects.
Technical Abstract: Rehabilitation, protection, and management of riverine backwaters (floodplain aquatic habitats that are seasonally or periodically connected to the main channel) are becoming increasingly common. General criteria for selecting restoration goals and evaluating alternative designs are lacking. An approach for assessing aquatic system status before and after restoration proposed by Kondolf and others (http://www.ecologyandsociety.org/vol11/iss2/art5/) is based on assigning a position to the system in a four-dimensional space that represents temporal variability on one axis and connectivity in the three spatial dimensions on the remaining three axes. Use of the Kondolf approach for evaluating restoration design for an example site is described. A plan featuring two small water control weirs was proposed, and a simple numerical water budget model was constructed to allow simulation of temporal variability and connectivity with the main river channel for any imposed annual hydrograph. The impact of varying backwater control structure (weir) design and operation on Kondolf position were assessed using the model.